JP3374675B2 - Hybrid vehicle and engine start control method - Google Patents

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a hybrid vehicle equipped with an engine and an electric motor as power sources, and more particularly to a technique for starting the engine.

[0002]

2. Description of the Related Art An engine operated by combustion energy of fuel and an electric motor operated by electric energy are provided as power sources for driving a vehicle, and an automatic transmission is provided between the power sources and driving wheels. The provided hybrid vehicle is described in, for example, Japanese Patent Application Laid-Open No. 7-67208. In such a hybrid vehicle,
For example, the engine consumption and the exhaust gas amount can be reduced while maintaining a predetermined traveling performance by selectively using the engine and the electric motor for traveling according to the operating state.

[0003]

By the way, in such a hybrid vehicle, it is possible not only to start the engine by a dedicated starter but also to start the engine by using an electric motor for traveling. In the past, no reference has been made to their proper use.

The present invention has been made in view of the above circumstances. An object of the present invention is to provide a hybrid vehicle equipped with an engine and an electric motor as a power source, by using a small and inexpensive starter to drive the engine. It is to be able to preferably start.

[0005]

In order to achieve the above object, the first aspect of the present invention is to provide (a) an engine that operates by combustion energy of fuel and an electric motor that operates by electric energy as a power source for vehicle traveling. As well as (b)
In a hybrid vehicle having a starter for starting the engine, (c) normally, the engine is cranked and started by the electric motor, but when starting by the electric motor is impossible, the starter It is characterized by having an engine start control means for cranking and starting the engine.

A second invention is a hybrid vehicle of the first invention.
In, the electric energy to drive the electric motor
If the storage device is equipped with a storage device and the storage device is insufficient
If it is impossible to start with the electric motor,
It is characterized by

The third invention is the same as the first or second invention.
In hybrid vehicles, when the electric motor fails
Note that it may be impossible to start the electric motor.
Characterize.

A fourth invention is any one of the first invention to the third invention.
Drive the electric motor in a hybrid vehicle
Equipped with a power storage device that stores electrical energy.
If the electric system including the data
The feature is that it is determined that the motor cannot be started.
To do.

A fifth invention is any one of the first invention to the fourth invention.
Cranking for a specified time
If the engine cannot be started after a certain period of time,
The feature is that it is judged that the start by the computer is impossible.
It

A sixth invention is any one of the first invention to the fifth invention.
Drive the starter in a hybrid vehicle
Having a low-voltage power storage device that stores electrical energy
Characterize.

[0011]

[0012]

[0013]

[0014]

[0015]

[0016] The seventh invention is to provide an engine that operates in the combustion energy of the fuel is provided as a power source while the vehicle is running, the electric motor that operates an electric energy of high voltage, the electric in order to start the engine It's a motor
In the engine start control method for a vehicle having a starter that operates at a much lower voltage, the electric motor is normally used to crank the engine to start the engine. However, when the electric motor cannot start the engine, the starter is used. It is characterized by cranking and starting the engine.

[0017] eighth invention, in the engine start control method of the seventh aspect of the present invention, includes a high-voltage energy storage device to store the electrical energy of the high voltage for driving the electric motor, its high voltage <br/> power storage device the storage amount When it is insufficient, it is determined that starting by the electric motor is impossible.

According to a ninth aspect of the present invention, in the engine start control method of the seventh aspect or the eighth aspect, it is determined that the electric motor cannot be started when the engine cannot be started even after a predetermined period of cranking. Is characterized by.

The tenth aspect of the present invention is based on the combustion energy of fuel.
The moving engine and motor generator are
It has a power source and starts the engine.
A hybrid vehicle with a starter for
Normally, the motor generator will drive the engine.
Start by ranking, but on that motor generator
If it is not possible to start the engine with the starter,
Engine start control means for cranking and starting the engine
It is characterized by having.

The eleventh aspect of the invention is based on the combustion energy of fuel.
Equipped with a moving engine as a power source when the vehicle is running
At the same time, start the motor generator and the engine.
Start control of a vehicle having a starter for
In the method, the motor generator is usually used to
The engine is cranked and started.
If the starter cannot be started with
Characterized by cranking and starting the engine
To do.

[0021]

[0022]

[0023]

In the hybrid vehicles of the first to sixth aspects of the invention , the electric motor for traveling the vehicle is usually used for cranking for starting the engine, so that the engine can be started quickly with a large torque. If the electric motor cannot start the engine due to a shortage of the amount of electricity stored in the electric storage device for the electric motor or a failure of the electric motor, the starter starts the engine.
It is possible to drive by the engine and charge the power storage device. Also, since the starter is used exceptionally, the number of times of use is small and the durability is improved, and the cranking time may be a little longer due to insufficient torque, so a small and inexpensive starter is used. it can.

[0024]

In the engine start control method of the seventh invention to the ninth invention, since an electric motor which operates with high voltage electric energy is usually used for cranking for starting the engine, the engine can be quickly operated with a large torque. To
In addition to being able to start the engine, if the high-voltage power storage device for the electric motor can not start the engine with the electric motor due to insufficient storage of the electric power or a failure of the electric motor, the starter will start the engine. And the power storage device can be charged. Also, since the starter is used exceptionally, the number of times of use is small and the durability is improved, and the cranking time may be a little longer due to insufficient torque, so a small and inexpensive starter is used. it can.

In the hybrid vehicle of the tenth invention
Is normally used to crank the engine to start the engine
Since a motor generator for both runs is used,
The engine can be started quickly with various torques and
The power storage device for the motor generator of
If the motor generator is damaged,
If the engine cannot be started, the starter
Since the engine is started, running and storage of electricity by the engine
The device can be charged. Also, the starter is used exceptionally.
Since it is only used, it is less durable and durable
In addition to improving, cranking time is long due to insufficient torque.
A small and inexpensive star as it can be a little long
Can be adopted. In the engine start control method of the eleventh invention
In general, a crankin for starting the engine
A motor generator is used for
If the power storage device for the generator is insufficient or the motor generator
Engine by motor generator due to malfunction of data
If the engine cannot be started, the starter will
Because it is started, it is driven by the engine and the power storage device is charged.
Is possible. Also starters are used exceptionally
Because it is a wreck, if it is used less often and durability is improved
In both cases, the cranking time is slightly longer due to insufficient torque.
Since it does not matter, you can use a small and inexpensive starter.
Wear.

[0027]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Here, the present invention relates to a switching type in which a power source is switched by connecting and disconnecting power transmission by, for example, a clutch, a combination of a planetary gear device, and the like.
The present invention can be applied to various types of hybrid vehicles including an engine and an electric motor as power sources during vehicle traveling, such as a mixed type in which outputs of the engine and the electric motor are combined or distributed by a distribution mechanism.

The electric storage device of the electric motor used when the vehicle is traveling generally has a high voltage (eg, 288 V),
The starter (starting motor) has the same low voltage (12V, etc.) as the power storage device that a normal engine-driven vehicle has.
A device that is operated by being supplied with electric power from the power storage device is preferably used. If a low-voltage power storage device with an external connection terminal is adopted, power can be easily supplied from a normal engine-driven vehicle through a booster cable when the power storage capacity is insufficient, and the starter can be operated to crank the engine. it can. The low-voltage power storage device can be used as a power source for auxiliary equipment such as an air conditioner, or can be charged from a high-voltage power storage device on the electric motor side using a voltage conversion device or the like. The generator that charges the power storage device may be provided separately from the electric motor, but a common motor generator can also be used.

In the first aspect of the present invention, when the engine cannot be started by the electric motor, for example, when the electric motor cannot be used due to insufficient storage of electricity, or when sufficient torque for starting the engine cannot be obtained even if the electric motor can be used, the electric This is the case where the operation and control of the electric motor cannot be performed (motor failure) due to a failure in the electric system including the motor itself or the power storage device, or the engine cannot be started even after a predetermined time has passed in cranking.

[0030]

Embodiments of the present invention will be described below in detail with reference to the drawings. FIG. 1 is a skeleton view of a hybrid drive system 10 for a hybrid vehicle that is an embodiment of the present invention. The hybrid drive device 10 is for an FR (front engine / rear drive) vehicle, and includes an engine 12 that operates by combustion energy of fuel, a motor generator 14 that functions as an electric motor and a generator that operates by electric energy, and a single A pinion type planetary gear unit 16 and an automatic transmission 18 are provided along the front-rear direction of the vehicle, and the left and right drive wheels (rear wheels) are output from the output shaft 19 via a propeller shaft or a differential device (not shown). Transmits power to. The planetary gear unit 16 is a composite distribution mechanism that mechanically combines and distributes forces, and constitutes an electric torque converter 24 together with the motor generator 14, and its ring gear 16
r is connected to the engine 12 via the first clutch CE ₁ , the sun gear 16 s is connected to the rotor shaft 14 r of the motor generator 14, and the carrier 16 c is the automatic transmission 18
Of the input shaft 26. Further, the sun gear 16s and the carrier 16c are the second clutch CE.
It is designed to be connected by _two . The output of the engine 12 is output via the flywheel 28 for suppressing rotation fluctuation and torque fluctuation and a damper device 30 made of an elastic member such as a spring and rubber to the first clutch CE ₁
Be transmitted to. Both the first clutch CE ₁ and the second clutch CE ₂ are friction type multi-disc clutches that are engaged and released by a hydraulic actuator.

The automatic transmission 18 is a combination of a sub-transmission 20 composed of a front-mounted overdrive planetary gear unit and a main transmission 22 composed of a simple-coupling 3 planetary gear train with four forward gears and one reverse gear. . Specifically, the auxiliary transmission 20 includes a single-pinion type planetary gear device 32, a hydraulic clutch C ₀ , a brake B ₀ frictionally engaged by a hydraulic actuator, and a one-way clutch F _0. Has been done. Main transmission 2
2 is three sets of single pinion type planetary gear units 34,
36, 38, hydraulic clutches C ₁ , C ₂ , frictionally engaged by hydraulic actuators, brakes B ₁ ,
And _{B 2, B 3, B 4} , is constituted by a one-way clutch F _1, F _2. The hydraulic circuit 44 is switched by energizing and de-energizing the solenoid valves SL1 to SL4 shown in FIG. 2, and the hydraulic circuit 44 is mechanically connected to the shift lever 40 as a shift operating means by a manual shift valve. Are mechanically switched, so that the clutches C ₀ and C that are engaging means.
_1, C _2, brake _{B 0, B 1, B 2} , B 3, B 4 are respectively engaged, are release control, a 5-speed neutral (N) as shown in FIG. 3 (1st~5th ), Each shift speed of the first reverse speed (Rev) is established. In addition,
The automatic transmission 18 and the electric torque converter 24 are configured substantially symmetrically with respect to the center line, and the lower half of the center line is omitted in FIG.

In the columns of clutch, brake and one-way clutch in FIG. 3, "○" indicates engagement, "●" indicates that the shift lever 40 is in the engine brake range, that is, "3", "2", or "L" range, Or "DM (Direct Mode)"
Engaged when operated to range and blank indicates disengaged. In that case, the neutral N, the reverse gear Rev, and the engine brake range are established by mechanically switching the hydraulic circuit 44 by a manual shift valve mechanically connected to the shift lever 40, and the shift lever 40 Is operated to the D (forward) range, the shift between 1st to 5th and the presence / absence of engine braking in the DM range are electrically controlled by solenoid valves SL1 to SL4. Further, the gear ratio of the forward gear is from 1st (first gear) to 5
As the gear ratio becomes th (fifth speed), the speed gradually decreases and the 4th speed ratio i ₄ = 1 (direct connection). The gear ratio shown in FIG. 3 is an example.

The shift lever 40 is, as shown in FIG. 8, "P (parking)", "R (reverse)", "N (neutral)", "D (drive)", "DM (direct mode)", It is possible to operate in a total of 9 operating ranges of "4", "3", "2", and "L", of which 6 operating positions in the up-down direction (vehicle front-rear direction) correspond to The manual shift valve is moved, and the six operating positions are detected by the shift position sensor 46. The "DM" range is a range in which the five forward shift stages (engine brake operation) can be manually switched, and the fact that the "DM" range has been operated is detected by the direct mode switch 41 (see FIG. 2). It has become. In the "DM" range, the shift lever 40 can be operated in the front-rear direction (vertical direction in the drawing), and the front-rear operation of the shift lever 40 in the "DM" range is detected by the + switch 42 and the-switch 43. At the same time, the automatic transmission 18 is upshifted according to the number of operations of the + switch 42, and downshifted according to the number of operations of the − switch 43.

The hydraulic circuit 44 comprises the circuit shown in FIG. In FIG. 4, reference numeral 70 represents a 1-2 shift valve, reference numeral 71 represents a 2-3 shift valve, and reference numeral 72 represents a 3-4 shift valve. The communication state of each port of these shift valves 70, 71 and 72 at each shift speed is as shown below the respective shift valves 70, 71 and 72. In addition, the number shows each gear stage.

Of the ports of the 2-3 shift valve 71, a third brake B ₃ is connected through an oil passage 75 to a brake port 74 which communicates with the input port 73 at the first speed and the second speed. . An orifice 76 is provided in this oil passage, and the orifice 76 and the third brake B are provided.
_A damper valve 77 is connected between the ₃ and the above. The damper valve 77, the line pressure P in the third brake B ₃
When L is suddenly supplied, a small amount of hydraulic pressure is sucked in to perform a buffering action.

The numeral 78 is a B-3 control valve, and controls the third engaging pressure of the brake B _3. That is, this B-3 control valve 78
Includes a spool 79, a plunger 80, and a spring 81 interposed therebetween, and an oil passage 75 is connected to an input port 82 opened and closed by the spool 79.
The output port 83 to be brought selectively communicating with the input port 82 is connected to the third brake B _3. Further, the output port 83 is connected to a feedback port 84 formed on the tip side of the spool 79. On the other hand, in the port 85 that opens at the location where the spring 81 is arranged, there is a port 86 that outputs the D range pressure (line pressure PL) at the third or higher shift speed among the ports of the 2-3 shift valve 71. They are communicated with each other via an oil passage 87. Further, a linear solenoid valve SLU is connected to a control port 88 formed on the end side of the plunger 80 so that the signal pressure P _SLU is acted on.
Therefore, the B-3 control valve 78 has a pressure regulation level set by the elastic force of the spring 81 and the hydraulic pressure supplied to the port 85, and the higher the signal pressure P _SLU supplied to the control port 88, the higher the signal pressure P _SLU is. The elastic force is increased.

Reference numeral 89 in FIG. 4 denotes a 2-3 timing valve, and the 2-3 timing valve 89.
Is arranged on the opposite side of the first plunger 91 with the spool 90 formed with a small-diameter land and two large-diameter lands, a first plunger 91, and a spring 92 arranged between them and the spool 90. Second plunger 9
3 and 3. An oil passage 95 is connected to an intermediate port 94 of the 2-3 timing valve 89, and this oil passage 95 is connected to the brake port 74 at a gear position higher than the third gear position among the ports of the 2-3 shift valve 71. It is connected to the port 96 which is communicated. The oil passage 95 is branched on the way and is connected to a port 97 opening between the small diameter land and the large diameter land via an orifice. The port 98 selectively connected to the port 94 is an oil passage. 99
It is connected to the solenoid relay valve 100 via. Then, the linear solenoid valve SLU is connected to the port opened at the end of the first plunger 91,
Further, the second brake B ₂ is connected to the port opening at the end of the second plunger 93 via the orifice.

The oil passage 87 is for supplying / discharging hydraulic pressure to / from the second brake B ₂ , and a small diameter orifice 101 and an orifice 102 with a check ball are interposed in the middle thereof. Further, the oil passage 103 branched from the oil passage 87, the large-diameter orifice 1 having a check ball to open when the pressure discharged from the second brake B ₂
04 is interposed, and this oil passage 103 is connected to an orifice control valve 105 described below.

The orifice control valve 105 is a valve for controlling the exhaust pressure speed from the second brake B ₂ , and the port 107 formed at the intermediate portion so as to be opened and closed by the spool 106 has the second brake B 2. ₂
The oil passage 103 is connected to a port 108 formed below the port 107 in the figure. A port 109 formed above the port 107 to which the second brake B ₂ is connected in the figure is a port that is selectively communicated with the drain port, and the port 109 is connected to the port 109 via an oil passage 110. The port 111 of the B-3 control valve 78 is connected. The port 111 is a port that is selectively communicated with the output port 83 to which the third brake B ₃ is connected.

Of the ports of the orifice control valve 105, a control port 112 formed at the end opposite to the spring for pressing the spool 106 is connected to the port 114 of the 3-4 shift valve 72 via the oil passage 113. ing. The port 114 outputs the signal pressure of the third solenoid valve SL3 at a gear speed lower than the third gear speed,
Further, it is a port for outputting the signal pressure of the fourth solenoid valve SL4 at a shift speed higher than the fourth shift speed. Further, the oil passage 9 is provided in the orifice control valve 105.
An oil passage 115 branched from 5 is connected, and the oil passage 115 is selectively connected to the drain port.

In the 2-3 shift valve 71, the port 116 for outputting the D range pressure at the gears below the second gear is opened at the location of the 2-3 timing valve 89 where the spring 92 is arranged. It is connected to the port 117 via an oil passage 118. A port 119 of the 3-4 shift valve 72, which is communicated with the oil passage 87 at a shift speed lower than the third shift speed, is connected to the solenoid relay valve 100 via the oil passage 120.

Reference numeral 121 indicates an accumulator for the second brake B ₂ , and the accumulator control pressure P _ac adjusted according to the signal pressure P _SLN output from the linear solenoid valve SLN is supplied to the back pressure chamber of the accumulator. It is like this. When the 2-3 shift valve 71 is switched during the 2 → 3 shift, the oil passage 8 is provided to the second brake B _2.
The D range pressure (line pressure PL) is supplied via 7, and the piston 121p of the accumulator 121 starts to rise due to this line pressure PL. This piston 12
While 1p is rising, the hydraulic pressure (engagement pressure) P _B2 supplied to the brake B ₂ is balanced with the downward biasing force of the spring 121s and the accumulator control pressure P _ac that biases the piston 121p downward. When the piston 121p reaches the rising end, the line pressure P is substantially constant, and strictly speaking, the spring 121s is gradually increased along with the compressive deformation of the spring 121s.
Can be raised to L. That is, the engagement pressure P _B2 at the time of gear shift transition in which the piston 121p moves is determined by the accumulator control pressure P _ac .

The accumulator control pressure P _ac is the engagement control of the second brake B ₂ when the third speed is established.
Other than the accumulator 121 for the
An accumulator for the clutch C ₁ which is engagement-controlled when the shift speed is established, an accumulator for clutch C ₂ which is engagement-controlled when the fourth shift stage is established, and a brake B ₀ which is engagement-controlled when the fifth shift stage is established. It is also supplied to the accumulator,
The transient hydraulic pressure at the time of engagement / disengagement of these is controlled.

Reference numeral 122 in FIG. 4 indicates a C-0 exhaust valve, and reference numeral 123 indicates an accumulator for the clutch C ₀ . The C-0 exhaust valve 122 operates to engage the clutch C ₀ in order to apply the engine brake only in the second gear in the second speed range.

According to such a hydraulic circuit 44, the shift from the second shift stage to the third shift stage, that is, the third brake B is performed.
_In the so-called clutch-to-clutch shift in which ₃ is released and the second brake B ₂ is engaged, the release transient hydraulic pressure of the third brake B ₃ and the engagement transient of the second brake B ₂ are based on the input torque of the input shaft 26 and the like. By controlling the hydraulic pressure, the shift shock can be appropriately reduced. For other shifts as well, the transient hydraulic pressures of the clutches C ₁ and C ₂ and the brake B ₀ are controlled by adjusting the accumulator control pressure P _ac by controlling the duty of the linear solenoid valve SLN.

The hybrid drive system 10 is provided with a hybrid control controller 50 and an automatic shift control controller 52, as shown in FIG. These controllers 50 and 52 are configured by including a microcomputer having a CPU, a RAM, a ROM, etc., and an accelerator operation amount sensor 62, a vehicle speed sensor 63, an input shaft rotation speed sensor 64, an engine water temperature sensor 65, a shift position sensor 46. From the accelerator operation amount θ _AC , the vehicle speed V (the rotation speed N of the output shaft 19 of the automatic transmission 18)
(Corresponding to _O ), the rotational speed N _I of the input shaft 26 of the automatic transmission 18, the engine water temperature TH _W , and the signal indicating the operating range of the shift lever 40 are supplied, as well as the engine torque T _E , the motor torque T _M , the engine Rotational speed N _E , motor rotational speed N _M , storage amount SOC of power storage devices 58 and 66 (see FIG. 5)
Information about ₁ , SOC ₂ , ON / OFF of the brake, etc. is supplied from various detecting means and the like, and signal processing is performed according to a preset program. The accelerator operation amount θ _AC is an operation amount of the accelerator operation means 48, such as an accelerator pedal, which is operated by the driver according to the output request amount. The engine torque T _E is obtained from the throttle valve opening and the fuel injection amount, and the motor torque T _M is obtained from the motor current.
₁ and SOC ₂ are obtained from the voltage values of the power storage devices 58 and 66, the motor current during charging when the motor generator 14 functions as a generator, the charging efficiency, and the like.

The output of the engine 12 is controlled in accordance with the operating state of the accelerator operation amount θ _{AC and the} like by controlling the throttle valve opening, the fuel injection amount, the ignition timing, etc. by the hybrid control controller 50. . The motor generator 14 has a high voltage (for example, 288 V) via an M / G controller (inverter) 56 as shown in FIG.
Connected to the electric power storage device 58 of the electric power storage device 58, and the hybrid control controller 50 supplies electric energy from the electric power storage device 58 to rotationally drive the electric power with a predetermined torque. Dynamic braking torque) to switch between a charging state in which the power storage device 58 is charged with electric energy by functioning as a generator and a no-load state in which the rotor shaft 14r is allowed to freely rotate. Also, the first clutch C
The E ₁ and the second clutch CE ₂ are switched between the engaged or disengaged state by switching the hydraulic circuit 44 via the solenoid valve or the like by the hybrid control controller 50.

The hybrid control controller 50
In order to start the engine 12, the starter (starting-only motor) 68 is operated to crank the engine 12 (rotate the crankshaft). The starter 68 is operated by being supplied with power from a power storage device 66 having the same low voltage (12 V, etc.) as a power storage device included in a general engine-driven vehicle, and the power storage device 66 has an external connection terminal. . The power storage device 66 is also connected to the M / G controller 56 and the power storage device 58 via a voltage conversion device 67 so that electric power can be transferred to and from them, and auxiliary equipment such as an air conditioner is also provided. It is also used as a power source for the class 69 and the controllers 50, 52.

Returning to FIG. 2, the automatic transmission 18 uses the automatic shift control controller 52 to control the solenoid valves SL1 to SL4 and the linear solenoid valve SL.
The excitation states of U, SLT and SLN are controlled, and the hydraulic circuit 4
4 is switched or hydraulic control is performed, the shift speed is automatically switched according to a shift pattern preset according to the operating state (for example, accelerator operation amount θ _AC and vehicle speed V).

The hybrid control controller 50 is
For example, Japanese Patent Application No. 7-29414 previously filed by the applicant of the present application
As described in No. 8, one of the nine operating modes shown in FIG. 7 is selected according to the flowchart shown in FIG. 6, and the engine 12 and the electric torque converter 24 are operated in the selected mode. Of the signal processing by the hybrid control controller 50, the part that executes each step in FIG. 6 functions as an operation mode switching unit that automatically switches a plurality of operation modes according to a predetermined mode switching condition.

In FIG. 6, in step S1, it is determined whether or not there is an engine start request, for example, to drive the engine 12 as a power source or to rotationally drive the motor generator 14 by the engine 12 to charge the power storage device 58. Is judged whether or not there is a command to start the engine 12, and if there is a start request, step S
The engine start routine of No. 2 is executed. The engine start routine is executed, for example, as shown in FIG. 9. Among the signal processing by the hybrid control controller 50, the portion that executes each step SA1 to SA5 in FIG. 9 is the engine start control according to claim 1 . It functions as a means.

In FIG. 9, it is determined in step SA1 whether the charged amount SOC ₁ of the high-voltage power storage device 58 is equal to or larger than a predetermined value α. If SOC ₁ <α, the starter 68 cranks the engine 12 in step SA5. At the same time, the fuel is injected and the engine 12 is started. The engine 12 is started with the first clutch CE ₁ released. The predetermined value α is, for example, the minimum amount of electricity required to crank and start the engine 12 by the motor generator 14.

If SOC ₁ ≧ α, step SA2 is executed after step SA1 to judge whether or not the motor fails by recording a diagnosis. The motor failure is a case where the operation and control of the motor generator 14 cannot be performed due to, for example, a failure of the motor generator 14 itself or a failure of an electric system including the power storage device 58. If it is not the motor failure, step SA3 is executed to judge whether or not a predetermined time T ₁ seconds which has been predetermined after the cranking of the engine 12 has started has elapsed, and the predetermined time T
If it is less than ₁ second, mode 9 is selected in step SA4. However, in the case of a motor failure or when a predetermined time T ₁ seconds has elapsed, step SA5 is executed and the starter 68 cranks the engine 12. The predetermined time T ₁ second is a time sufficient for cranking and starting the engine 12 in the execution of the mode 9.

The mode 9 selected in step SA4 is
As is apparent from FIG. 7, the first clutch CE ₁ is engaged (O
N), the second clutch CE ₂ is engaged (ON), the engine 12 is cranked by the motor generator 14 via the planetary gear device 16, and fuel injection is performed to start the engine 12. The mode 9 is performed by setting the automatic transmission 18 to the neutral state when the vehicle is stopped, and when traveling with only the motor generator 14 that has released the first clutch CE ₁ as the power source like the mode 1, the first clutch CE ₁ Is performed and the motor generator 14 is operated with an output higher than the required output required for traveling, and the engine 12 is rotationally driven with a margin output higher than the required output. Further, even when the vehicle is traveling, it is possible to temporarily set the automatic transmission 18 to neutral and execute the mode 9. In some cases, the engine 12 can be cranked by the motor generator 14 with the second clutch CE ₂ released.

Returning to FIG. 6, if the determination in step S1 is negative, that is, if there is no engine start request, step S3 is executed to determine whether or not there is a braking force request, for example. Whether the brake is ON, the operation range of the shift lever 40 is the engine brake range such as L or 2, or the DM range, and the accelerator operation amount θ.
Whether or not _AC is 0, or simply whether or not the accelerator operation amount θ _AC is 0 is determined. When this judgment is affirmed, step S4 is executed. In step S4, the stored power amount SOC ₁ of the power storage device 58 is the predetermined maximum stored power amount B.
It is determined whether or not the above, and if SOC ₁ ≧ B, step S
In mode 5, mode 8 is selected. If SOC ₁ <B, mode 6 is selected in step S6. The maximum storage amount B is the maximum storage amount allowed to charge the storage device 58 with electric energy, and is set to a value of, for example, about 80% based on the charging / discharging efficiency of the storage device 58.

Mode 8 selected in step S5
Engages (ON) the first clutch CE ₁ and engages (ON) the second clutch CE ₂ as shown in FIG.
Is stopped, that is, the throttle valve is closed and the fuel injection amount is set to 0, whereby the braking force by the frictional rotation of the engine 12 and the pump action, that is, the engine brake is applied to the vehicle, and the brake operation by the driver is performed. Is reduced and driving operation becomes easier. Further, since the motor generator 14 is in a no-load state and is allowed to freely rotate, it is possible to prevent the storage amount SOC ₁ of the power storage device 58 from becoming excessive and impairing performance such as charge / discharge efficiency.

In mode 6 selected in step S6, as is apparent from FIG. 7, the first clutch CE ₁ is released (OF
F), the second clutch CE ₂ is engaged (ON), the engine 12 is stopped, and the motor generator 14 is charged. By the kinetic energy of the vehicle, the motor generator 14 is driven to rotate, Since the power storage device 58 is charged and a regenerative braking force such as an engine brake is applied to the vehicle, braking operation by the driver is reduced and driving operation is facilitated. Further, since the first clutch CE ₁ is released and the engine 12 is shut off, there is no energy loss due to the rotational resistance of the engine 12, and it is executed when the charged amount SOC ₁ is less than the maximum charged amount B. , The storage amount SO of the storage device 58
C ₁ does not become excessive and the performance such as charge / discharge efficiency is not impaired.

If the determination in step S3 is negative, that is, if the braking force is not requested, step S7 is executed to determine whether or not the engine start is requested, for example, the engine 12 such as mode 3 as a power source. It is determined by whether or not the vehicle is stopped during running, that is, whether or not the vehicle speed V≈0. If this determination is affirmative, it is determined in step S8 whether or not the accelerator is ON, that is, whether or not the accelerator operation amount θ _AC is larger than a predetermined value of substantially zero, and if the accelerator is ON, in step S9. If mode 5 is selected and the accelerator is not ON, mode 7 is selected in step S10.

Mode 5 selected in step S9
As shown in FIG. 7, the first clutch CE ₁ is engaged (ON) and the second clutch CE ₂ is released (OFF),
With the engine 12 in operation, the motor generator 14
The vehicle is started by controlling the regenerative braking torque of. More specifically, the planetary gear device 1
When the gear ratio of 6 is ρ _E , engine torque T _E : output torque of planetary gear device 16: motor torque T _M = 1:
Since (1 + ρ _E ): ρ _E , for example, assuming that the gear ratio ρ _E is about 0.5 which is a general value, the engine torque T
_{Since the} motor generator 14 shares half the torque of _E , the carrier 16c outputs about 1.5 times the engine torque T _E. That is, it is possible to start a high torque that is (1 + ρ _E ) / ρ _E times the torque of the motor generator 14. Further, if the motor current is cut off and the motor generator 14 is put into a no-load state, the output from the carrier 16c becomes 0 only by the reverse rotation of the rotor shaft 14r, and the vehicle is stopped.
That is, the planetary gear device 16 in this case functions as a starting clutch and a torque amplifying device, and the engine torque T is increased by gradually increasing the motor torque (regenerative braking torque) T _M from 0. _The vehicle can be smoothly started with an output torque that is (1 + ρ _E ) times _E.

Here, in this embodiment, a motor generator having a torque capacity approximately ρ _E times the maximum torque of the engine 12, that is, a motor generator 14 which is as small as possible and has a small capacity while securing a required torque is used. ,
The device is compact and inexpensive. Further, in this embodiment, the output of the engine 12 is increased by increasing the throttle valve opening and the fuel injection amount in response to the increase of the motor torque T _M , and the engine rotation accompanying the increase of the reaction force is performed. This prevents engine stalls and the like due to the decrease in the number N _E.

The mode 7 selected in step S10 is
As is apparent from FIG. 7, the first clutch CE ₁ is engaged (O
N), the second clutch CE ₂ is released (OFF), the engine 12 is put into an operating state, and the motor generator 14 is put into an unloaded state to be electrically neutral. The rotor shaft 14r of the motor generator 14 is in the reverse direction. When the automatic transmission 18 is freely rotated, the output of the automatic transmission 18 to the input shaft 26 becomes zero. This allows
It is not necessary to stop the engine 12 one by one when the vehicle is stopped while the vehicle is running with the engine 12 as the power source, such as in mode 3, and it is possible to substantially start the engine in mode 5.

If the determination in step S7 is negative, that is, if there is no request to start the engine, step S1
1 is executed to determine whether the required output Pd is less than or equal to the preset first determination value P1. The required output Pd is an output required for running the vehicle including running resistance, and is the accelerator operation amount θ _AC.
And rate of change thereof, the vehicle speed V (output speed N _O), based on such gear position of the automatic transmission 18 is calculated by such a predetermined data map or an arithmetic expression. The first determination value P1 is a boundary value between a medium load region in which only the engine 12 is used as a power source and a low load region in which only the motor generator 14 is used as a power source, and the energy efficiency including the time of charging by the engine 12 is included. In consideration of the above, the amount of exhaust gas and the amount of fuel consumption are determined by experiments and the like so as to be as small as possible.

If the determination in step S11 is affirmative,
That is, when the required output Pd is less than or equal to the first determination value P1, it is determined in step S12 whether or not the storage amount SOC ₁ is greater than or equal to the preset minimum storage amount A, and if SOC ₁ ≧ A, in step S13. Select mode 1 while SOC ₁
<If A, mode 3 is selected in step S14. The minimum storage amount A is the minimum storage amount that allows the electric energy to be extracted from the storage device 58 when traveling with the motor generator 14 as the power source.
For example, a value of about 70% is set based on the charging / discharging efficiency of the above. Predetermined value α in step SA1 of FIG. 9
Is a value that is sufficiently smaller than this minimum storage amount A,
It is also possible to set a value similar to the minimum storage amount A.

In the mode 1, as is apparent from FIG. 7, the first clutch CE ₁ is released (OFF), the second clutch CE ₂ is engaged (ON), the engine 12 is stopped,
The motor generator 14 is rotationally driven at the required output Pd, and the vehicle is run using only the motor generator 14 as a power source. Also in this case, since the first clutch CE ₁ is released and the engine 12 is shut off, the friction loss is small as in the case of the mode 6, and the automatic transmission 18 is appropriately controlled to shift gears to drive the motor efficiently. It can be controlled. Further, this mode 1 is executed when the required output Pd is in the low load region where the first determination value P1 is less than or equal to and the storage amount SOC ₁ of the power storage device 58 is equal to or more than the minimum storage amount A. The energy efficiency is superior to the case where the vehicle travels as, the fuel consumption and exhaust gas can be reduced, and the storage amount SOC ₁ of the power storage device 58 does not fall below the minimum storage amount A and the performance such as charging / discharging efficiency is not impaired.

The mode 3 selected in step S14 is
As is apparent from FIG. 7, the first clutch CE ₁ and the second clutch CE ₁
The clutch CE ₂ is both engaged (ON) to bring the engine 12 into an operating state and the motor generator 14 into a charged state by regenerative braking, which is generated by the motor generator 14 while the vehicle is being driven by the output of the engine 12. Electric power storage device 58 is charged with electric energy. The engine 12 is operated at an output equal to or higher than the required output Pd, and current control of the motor generator 14 is performed so that the motor generator 14 consumes an amount of surplus power larger than the required output Pd.

If the determination in step S11 is negative,
That is, when the required output Pd is larger than the first determination value P1, whether or not the required output Pd is larger than the first determination value P1 and smaller than the second determination value P2 in step S15.
That is, it is determined whether P1 <Pd <P2. The second determination value P2 is determined by the engine 12 and the motor generator 14 in the medium load region where the engine 12 alone is used as a power source for traveling.
Is the boundary value of the high load region where the vehicle runs with both of them as power sources, and in consideration of the energy efficiency including the time of charging by the engine 12, the exhaust gas amount, the fuel consumption amount, etc. are preliminarily determined by experiments or the like so as to be as small as possible. It is set.
If P1 <Pd <P2, then in step S16, S
It is determined whether OC ₁ ≧ A. If SOC ₁ ≧ A, mode 2 is selected in step S17. If SOC ₁ <A, mode 3 is selected in step S14. Also,
If pd ≧ P2 is determined whether SOC ₁ ≧ A in step S18, when the SOC ₁ ≧ A selects the mode 4 in the step S19, when the SOC ₁ <A step S
In mode 17, mode 2 is selected.

In the mode 2, as is apparent from FIG. 7, the first clutch CE ₁ and the second clutch CE ₂ are both engaged (ON), the engine 12 is operated at the required output Pd, and the motor generator 14 is operated. It is a no-load state, and the vehicle is run using only the engine 12 as a power source. Further, in mode 4, the first clutch CE ₁ and the second clutch CE ₁
The clutch CE ₂ is both engaged (ON) to bring the engine 12 into an operating state and the motor generator 14 is rotationally driven, and the vehicle is driven with high output using both the engine 12 and the motor generator 14 as power sources. This mode 4 is executed in the high load region where the required output Pd is equal to or higher than the second determination value P2, but since the engine 12 and the motor generator 14 are used together, only one of the engine 12 and the motor generator 14 is used. Compared with the case of traveling as a power source, energy efficiency is not significantly impaired, and fuel consumption and exhaust gas can be reduced. Further, since the electricity storage amount SOC ₁ is executed when the above minimum storage amount A, the storage amount SOC ₁ of power storage device 58 does not impair the performance of the charge-discharge efficiency and the like and lower than the minimum storage amount A.

To summarize the operating conditions of the above modes 1 to 4, if the charged amount SOC ₁ ≧ A, the mode 1 is selected in step S13 in the low load region of Pd ≦ P1 and only the motor generator 14 is used as the power source. Drive, P1 <
In the medium load region of Pd <P2, the mode 2 is set in step S17.
To drive with only the engine 12 as the power source,
In the high load region of 2 ≦ Pd, the mode 4 is selected in step S19, and both the engine 12 and the motor generator 14 are used as power sources for traveling. If SOC ₁ <A, the power storage device 58 is charged by executing the mode 3 of step S14 in the medium and low load region in which the required output Pd is smaller than the second determination value P2, but the required output Pd is In the high load region of 2 determination value P2 or more, the mode 2 is selected in step S17, and the engine 12 runs at high output without charging.

In the mode 2 of step S17, P1 <Pd
This is executed when <P2 is in the medium load region and SOC ₁ ≧ A, or when Pd is ≧ P2 in the high load region and SOC ₁ <A. Since the energy efficiency is better, the fuel consumption and the exhaust gas can be reduced as compared with the case of traveling with the motor generator 14 as the power source. Further, in the high load region, the mode 4 in which the motor generator 14 and the engine 12 are used together for traveling is desirable,
When the storage amount SOC ₁ of the power storage device 58 is smaller than the minimum storage amount A, the operation is performed in mode 2 using only the engine 12 as a power source, so that the storage amount SOC ₁ of the storage device 58 is the minimum storage amount A. It is avoided that it becomes less than A and impairs performance such as charge and discharge efficiency.

In the hybrid drive system 10 of this embodiment as described above, the motor generator 14 for running the vehicle is usually used for cranking for starting the engine 12.
Is used, the engine 12 can be quickly started with a large torque, and the motor generator 14
6 when the amount of power stored in the high-voltage power storage device 58 for the vehicle is insufficient, the motor fails, or the cranking time by the motor generator 14 exceeds a predetermined time T ₁ second.
Since the engine 12 is started by 8, the vehicle can be driven by the engine 12 and the power storage device 58 can be charged except when the motor fails.

Further, since the starter 68 is used only exceptionally, the number of times of use is small and the durability is improved, and the cranking time may be a little longer due to insufficient torque. Therefore, the starter 68 is small and inexpensive. A starter that can be used.

The starter 68 is operated by being supplied with electric power from a low-voltage power storage device 66 provided in a general engine-driven vehicle, and the power storage device 66 has an external connection terminal. When both 58 and 66 have insufficient power storage amount, electric power can be easily supplied from a general engine-driven vehicle through a booster cable or the like. As a result, the engine 12 can be cranked and started by the starter 68, power can be generated by the motor generator 14 to charge the power storage devices 58 and 66, and a charging device for high voltage is not required, which reduces costs. Reduction and improvement of reliability can be achieved.

The above embodiment is an embodiment of the invention described in claims 1 to 11 .

FIG . 10 is a flowchart executed in place of FIG.

In FIG. 10, in step SB1, it is determined whether the engine water temperature TH _W is a predetermined value β or more, and TH _W
If <β, the engine 12 is cranked by the starter 68 and the mode 9 in step SB5 to start the engine 12. That is, the engine 12 is cranked by both the starter 68 and the motor generator 14. The predetermined value β is, for example, such a low temperature that the rotation resistance of the engine 12 is large and the starter 68 alone cannot crank and start the engine 12.

If TH _W ≧ β, step SB1 is executed after step SB1 to judge whether or not the starter fails by recording the diagnosis. The starter failure is a case where the operation or control of the starter 68 is impossible due to a failure of the starter 68 itself or a failure of an electric system including the power storage device 66. If it is not a starter fail, step SB3 is executed to determine whether or not a predetermined time T ₂ seconds which has been predetermined after starting cranking of the engine 12 has elapsed, and if it is within the predetermined time T ₂ seconds, step SB4 is executed, but in the case of a starter failure or when the predetermined time T ₂ seconds has elapsed, the above step SB5 is executed.
To execute. Step SB4 is a step in which the engine 12 is cranked and started only by the starter 68.
During the predetermined time T ₂ seconds, the engine 1 is operated only by the starter 68.
Sufficient time to crank and start the 2. The engine 12 is started only by the starter 68 while the first clutch CE ₁ is released.

In the present embodiment, the engine 12 is normally cranked and started by the starter 68, but when the engine water temperature TH _W is low, the starter fails, or the cranking time by the starter 68 is a predetermined time T ₂ seconds. When the time elapses, the mode 9 is additionally executed, and the cranking of the engine 12 is assisted by the motor generator 14. Therefore, the small-sized and inexpensive starter 6 having a small torque is executed.
8 can be adopted. Further, even when the engine 12 cannot be started only by the starter 68, the motor generator 1
Since cranking is assisted by 4 and the engine 12 can be started, traveling by the engine 12 and charging of the power storage device 66 are possible.

In step SB5, the starter 68 and the mode 9 are executed to crank the engine 12, but the mode 9 alone, that is, the motor generator 14 alone is used without operating the starter 68. 12 may be cranked and started.

Although the embodiments of the present invention have been described in detail with reference to the drawings, the present invention can be implemented in other modes.

For example, in the above-described embodiment, the automatic transmission 18 having the reverse speed 1 step and the forward speed 5 step is used, but as shown in FIG. 11, the auxiliary transmission 20 is omitted and the main transmission is omitted. It is also possible to employ the automatic transmission 60 composed of only 22 and perform the shift control with four forward gears and one reverse gear as shown in FIG. However, the present invention can be applied to a hybrid vehicle that does not include such a transmission.

Although not illustrated one by one, the present invention can be carried out in various modified and improved modes based on the knowledge of those skilled in the art.

[Brief description of drawings]

FIG. 1 is a skeleton diagram illustrating a configuration of a hybrid drive system for a hybrid vehicle that is an embodiment of the present invention.

FIG. 2 is a diagram illustrating a control system included in the hybrid drive device in FIG.

FIG. 3 is a diagram illustrating an operation of an engagement element that establishes each shift speed of the automatic transmission of FIG.

FIG. 4 is a diagram showing a part of a hydraulic circuit provided in the automatic transmission of FIG.

5 is a diagram illustrating a connection relationship between the hybrid control controller of FIG. 2 and an electric torque converter or the like.

FIG. 6 is a flowchart illustrating a basic operation of the hybrid drive system of FIG.

7] Modes 1 to 9 in the flowchart of FIG.
It is a figure explaining the operating state of.

FIG. 8 is a diagram showing an example of an operation pattern of a shift lever.

FIG. 9 is a diagram showing an example of a flowchart for explaining the specific contents of the engine start routine of step S2 in FIG. 6, which is an embodiment of the invention described in claims 1 to 11 ;

FIG. 10 is a diagram showing another example of the flowchart for explaining the specific contents of the engine start routine of step S2 in FIG.

FIG. 11 is a skeleton view illustrating another example of a hybrid drive system of a hybrid vehicle to which the present invention is preferably applied.

FIG. 12 is a diagram illustrating an operation of an engagement element that establishes each shift speed of the automatic transmission of FIG. 11.

[Explanation of symbols]

12: engine 14: motor generator (electric motor) 50: controller for hybrid control 58: power storage device (high voltage power storage device) 66: low voltage power storage device 68: starter steps SA1 to SA5: engine start control means (claim 1 , 10)

─────────────────────────────────────────────────── ─── Continuation of the front page (51) Int.Cl. ⁷ Identification code FI B60K 6/04 733 B60K 6/04 733 F02D 29/02 F02D 29/02 D F02N 11/00 F02N 11/00 K 11/04 11 / 04 D (72) Inventor Yushi Hata 1 Toyota Town, Toyota City, Aichi Prefecture, Toyota Motor Co., Ltd. (72) Inventor Tsuyoshi Mikami 1 Toyota Town, Toyota City, Aichi Prefecture, Toyota Motor Co., Ltd. (56) Reference References JP-A-8-93517 (JP, A) JP-A-11-117837 (JP, A) JP-A-8-170533 (JP, A) Actually open Sho 60-102471 (JP, U) Actually open 6- 25556 (JP, U) Actual Kaihei 4-128004 (JP, U) (58) Fields investigated (Int.Cl. ⁷ , DB name) B60K 6/02-6/04 B60L 11/02-11/14 F02D 29/02-29/06 F02N 11/00-11/04

Claims (11)

(57) [Claims] 1. A hybrid vehicle comprising an engine that operates with combustion energy of fuel and an electric motor that operates with electric energy as power sources when the vehicle is running, and a starter for starting the engine. Normally, the engine is cranked and started by the electric motor, but when the electric motor cannot be started, the engine start control means for cranking and starting the engine by the starter is provided. Hybrid vehicle. 2. An electric storage device for storing electric energy for driving the electric motor, wherein when the electric storage device has an insufficient amount of electric storage, it is determined that the electric motor cannot be started. The hybrid vehicle described in. 3. The hybrid vehicle according to claim 1, wherein it is determined that the electric motor cannot be started when the electric motor fails. 4. A power storage device for storing electric energy for driving the electric motor, wherein when the electric motor itself or an electric system including the power storage device fails, it is determined that the electric motor cannot be started. The hybrid vehicle according to any one of claims 1 to 3. 5. The method according to claim 1, wherein when the engine cannot be started even after cranking for a predetermined time, it is determined that the electric motor cannot be started.
The hybrid vehicle according to any one of 1. 6. The hybrid vehicle according to claim 1, further comprising a low-voltage power storage device that stores electric energy for driving the starter. 7. A engine operating at combustion energy of the fuel with includes as a power source while the vehicle is running, the high
An electric motor that operates an electric energy of a voltage at lower voltage than the electric motor for starting the engine
In an engine start control method for a vehicle having a starter that operates, the engine is normally cranked and started by the electric motor. However, when starting by the electric motor is impossible, the engine is stopped by the starter. An engine start control method characterized by ranking and starting. 8. with a high voltage energy storage device to store the electrical energy of the high voltage for driving the electric motor, said high voltage蓄<br/> collector is in impossible is started by the electric motor in the case of insufficient storage amount The engine start control method according to claim 7 , wherein it is determined that there is. 9. Claim 7 cranking is characterized in that it is determined that the impossible is started by the electric motor if it can not start the engine even after the elapse of a predetermined time or
8. The engine start control method according to item 8 . 10. An engine operating with fuel combustion energy.
The gin and the motor generator are used as power sources when the vehicle is running.
And to start the engine
In a hybrid vehicle with a starter of Normally, the engine is clamped by the motor generator.
It starts by being locked by the motor generator.
If it is not possible to operate the engine with the starter,
Engine start control means for starting
And a hybrid vehicle. 11. An engine operating with fuel combustion energy.
In addition to being equipped with a gin as a power source for running the vehicle,
For starting the motor generator and the engine
An engine start control method for a vehicle having a starter
hand, Normally, the engine is clamped by the motor generator.
It starts by being locked by the motor generator.
If it is not possible to operate the engine with the starter,
Engine start system characterized by starting by cranking
Way.